From U.S. Pat. No. 4,555,980 such a device is disclosed wherein the fastening unit could be considered to comprise an integral part of the end wall itself, said part comprising threaded holes for co-operation with locking screws for the respective bands and wherein a distance plate is insertable into a cavity in the end wall.
The known device, however, does not fully fulfil the requirements for position accuracy with respect to the bands emanating from the end wall and with respect to simple production, simple assembly and thus totally a competitive cost for the required function.
It is an aim of this invention to develop a device according to the known art so as to obtain safe function at a more competitive cost.
This aim is achieved in a device as above by the feature of the characterizing portion of the claim.